Subdural hematomas continue to be a challenging set of pathology for neurosurgeons given today's aging population. Patients with symptomatic subacute and chronic subdural hematomas are frequently elderly and commonly have multiple coexisting medical conditions. Typically patients present after a remote history of trauma, though often trivial, with progressive neurologic deficits including hemiparesis, gait instability, and cognitive decline to name a few: Ramachandran R, Thimmappa H. “Chronic subdural hematomas—causes of morbidity and mortality.” Surg Neurol 2007:67; 367-373. The mortality rate for this pathology even with treatment, often cited at a range of 2-6%, is significant given the frequency of symptomatic presentation. Sucu H K, Gokmen M, Ergin A, Bezircioglu, Gokemn A. “Is there a way to avoid surgical complications of twist drill craniostomy for evacuation of a chronic subdural hematoma.” Acta Neurochir (Wien) 2007; 149:597-599; Ernestus R I, Beldzinski P, Lanfermann H, Klug N. “Chronic subdural hematoma: Surgical treatment and outcome in 104 patients.” Surg Neurol 1997; 48:220-225; Mellergard P, Wisten O. “Operations and re-operations for chronic subdural haematomas during a 25-year period in a well defined population: Acta Neurochir (Wien) 1996; 138:708-713; and Merlicco G, Pierangeli E, di Padova P L. “Chronic subdural hematomas in adults: prognostic factors.” Analysis of 70 cases. Neurosurg Rev 1995; 18:247-251. Multiple treatment modalities have been described and advocated in the literature. The most extreme is a standard craniotomy under general anesthesia for hematoma evacuation and membrane removal, if present. Alternatively, isolated or multiple bur holes may be drilled to permit hematoma irrigation and removal. More recently, placement of a tangential drainage catheter within the subdural space via a twist-drill craniostomy had been practiced typically under monitored sedation, but catheter obstruction and cessation of flow is often encountered.
A subdural evacuation port system (or “SEPS”) available from Medtronic, Inc., Minneapolis, Minn., has seen recent use. As illustrated in FIG. 1, a SEPS device 10 is essentially a hollow screw placed in the skull 20 which communicates with the subdural space 22 and is attached to closed system suction device (not shown). Asfora W T, Schwebach L. “A modified technique to treat chronic and subacute subdural hematoma: technical report.” Surg Neural 2003; 59:329-332. While the device 10 has appeared more successful that the tangential subdural catheter technique and can be performed without general anesthesia, it is potentially complicated by portal obstruction prior to adequate hematoma evacuation.
Indeed, recent experience of one surgical group with the SEPS device indicates that approximately one third of patients treated had less than half of the hematoma volume evacuated. This subsequently resulted in approximately one quarter of the patients requiring an additional surgical procedure to adequately evacuate the hematoma due to inability to restore drainage of fluid through this system after it became occluded. One could open the system to clear occlusions by insert a trochar, but this potentially breaks sterility, and insertion of a trochar or other tool raises the potential of injuring underlying brain tissue. Hence, there is a need for new devices for the treatment of subdural hematoma.